''Gastrodia zeylanica'' is a species of potato orchids which is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to Sri Lanka. It was added to the ''2007 Red list of Threatened Fauna and Flora of Sri Lanka'' as ' critically endangered', on the basis of it having only been collected from a few localities.

Taxonomy

It was first reported from Sri Lanka in 1864 by George Henry Kendrick Thwaites, who classified it as '' Gastrodia javanica'', this was followed by subsequent authors until 1906, when Rudolf Schlechter described the Sri Lankan specimens as a new species which he called ''G. zeylanica''. In 2019 it was synonymized as ''Demorchis zeylanica'' (''Demorchis'' is a synonym of ''

Gastrodia ''Gastrodia'', commonly known as potato orchids or as 天麻属 (tian ma shu), is a genus of terrestrial leafless orchids in the family Orchidaceae, about ninety of which have been described. Orchids in this genus have fleshy, upright stems and ...

''), by

Mark Alwin Clements Mark Alwin Clements (b. 1949) is an Australian botanist and orchidologist. He obtained his doctorate at the Australian National University defending his thesis entitled ''Reproductive Biology in relation to phylogeny of the Orchidaceae, espe ...

and David Lloyd Jones.

Distribution

It is native to southwest Sri Lanka. In the 1981 ''A Revised handbook to the flora of Ceylon'', Jayaweera mistakenly included illustrations of a ''

Didymoplexis ''Didymoplexis'', commonly known as crystal orchids or as 双唇兰属 (shuang chun lan shu), is a genus of terrestrial leafless orchids in the family Orchidaceae, about twenty species of which have been described. Orchids in this genus have sw ...

'', possibly ''D. pallens'', titled as ''Gastrodia zeylanica'', and based on these illustrations Khan and Halam identified ''G. zeylanica'' as occurring in Bangladesh in 1989. This belief was maintained in ''Our present knowledge on the Terrestrial Orchidaceae'' by Khanam ''et al''. Jayaweera's mistake was first pointed out by Fernando and Ormerod in their 2008 publication ''An Annotated Checklist of the Orchids of Sri Lanka''.

References

Orchids of Sri Lanka Plants described in 1906 zeylanica {{Epidendroideae-stub